The environment contains a variety of infectious microbial agents, such as viruses, bacteria, fungi and parasites, any one of which can cause pathological damage to the host organism. Consequently, most organisms, such as mammals, i.e. humans, have developed an immune system. The immune system is divided into two functional divisions, the innate immune system and the adaptive immune system.
The innate and adaptive immune systems consists of a variety of molecules and cells distributed throughout the body. The most important cells are leukocytes. Leukocytes are categorized as phagocytes, including polymorphonuclear neutrophils (PMNs), monocytes and macrophages, and lymphocytes, which mediate adaptive immunity.
Inflammation is the body""s response to invasion or an injury, such as an invasion by an infectious microbial agent and includes three broad actions. First, the blood supply is increased to the area. Second, capillary permeability is increased, thereby permitting larger molecules to reach the site of infection. Third, leukocytes, particularly PMNs, migrate out of the capillaries and into the surrounding tissue. Once in the tissue, the PMNs migrate to the site of infection or injury by chemotaxis. These events manifest themselves as inflammation. Examples of conditions which cause these reactions to occur include clamping or tourniquet vessel-induced ischemia reperfusion injury, chronic inflammatory conditions such as asthma, rheumatoid arthritis, and inflammatory bowel disease, as well as autoimmune diseases.
Aberrant activation of phagocytic cells, in particular neutrophils, leads to the generation of superoxide anion, which when released to the extracellular milieu can evoke damage to surrounding tissues. Reactive oxygen species derived from neutrophil oxygen burst can play a deleterious role in generating secondary products that lead to loss of function. During surgery, in particular clamping of vessels, there is clear evidence that reperfusion following the release of the clamp involves neutrophil-derived mediators. The neutrophil-derived oxygen radicals and other toxic products that are normally intended for killing of microbial agents once they spill over into the surrounding tissue can lead to second organ injury, most notably in the lung and cardiac tissues, sequelae which are observed following ischemia reperfusion injury (Welbourn et al., Brit. J. Surg. 1991; 78:651-655).
Once at the site of infection, PMNs perform phagocytic and degradative functions to combat the infectious agent. As part of the response to the infectious agent, PMNs generate superoxide anions, reactive oxygen species (ROS) to kill infested material and adhere to epithelial cells of mucosal surfaces or vascular endothelial cells of the blood vessels. As a consequence, the host can experience undesirable side effects during the elimination of the infectious agent such as, pain, swelling about the site, and nausea.
The present invention relates to novel presqualene diphosphate (PSDP) analogs and their use.
In one embodiment, the present invention is directed to a PSDP analog having an active region of natural PSDP and a metabolic transformation region resistant to in vivo metabolism. For example, the analog can inhibit leukocyte activation, leukocyte generation of active oxygen species, adhesion between a leukocyte cell and an epithelial cell or an endothelial cell or leukocyte generation of reactive oxygen species (ROS).
In another embodiment, the present invention is directed to a method for treating or preventing inflammation and/or an inflammatory response in the subject. The method includes administering to a subject an anti-inflammatory amount of a PSDP analog having an active region of natural PSDP and a metabolic transformation region resistant to in vivo metabolism.
In yet another embodiment, the present invention is directed to a compound represented by one of the formulae (Formulae I-IV): 
R1, R2 and R3 are each independently, selected from the group consisting of hydrogen, F, Cl, Br, I, CH3 and substituted or unsubstituted, linear or branched alkyl, alkoxy, aryl, aralkyl or heteroaryl groups. Y1, Y2, Y3, Y4, and Y5 are each independently selected from hydrogen atoms or lower alkyl groups. X1 is an oxygen atom, a sulfur atom, an Nxe2x95x90N group, a methylene or, NR5, wherein R5 is a hydrogen atom or a substituted or unsubstituted, linear or branched alkyl, aryl, aralkyl or heteroaryl group. X2 is an OH group, SH, CH3, or NR6R7, wherein R6 and R7 are each independently, a hydrogen atom or a substituted or unsubstituted, linear or branched alkyl, aryl, aralkyl or heteroaryl group. A1, A2, A3, and A4 are each independently, a substituted or unsubstituted aromatic or nonaromatic carbocyclic or heterocyclic group. Preferably, carbonxe2x80x94carbon bonds are not formed between one or more of C1 and C4, C2 and C5, and C3 and C6 carbon atoms. Salts of Formulae I-IV are also included in the present invention.
In yet another embodiment, the present invention is directed to a pharmaceutical composition comprising an effective amount of a compound represented by one or more of the formulae (Formulae I-IV): 
R1, R2 and R3 are each independently, selected from the group consisting of hydrogen, F, Cl, Br, I, CH3 and substituted or unsubstituted, linear or branched alkyl, alkoxy, aryl, aralkyl or heteroaryl groups. Y1, Y2, Y3, Y4, and Y5 are each independently selected from hydrogen atoms or lower alkyl groups. X1 is an oxygen atom, a sulfur atom, an Nxe2x95x90N group, a methylene or, NR5, wherein R5 is a hydrogen atom or a substituted or unsubstituted, linear or branched alkyl, aryl, aralkyl or heteroaryl group. X2 is an OH group, SH, CH3, or NR6R7, wherein R6 and R7 are each independently, a hydrogen atom or a substituted or unsubstituted, linear or branched alkyl, aryl, aralkyl or heteroaryl group. A1, A2, A3, and A4 are each independently, a substituted or unsubstituted aromatic or nonaromatic carbocyclic or heterocyclic group. Preferably, carbonxe2x80x94carbon bonds are not formed between one or more of C1 and C4, C2 and C5, and C3 and C6 carbon atoms. The present invention also includes pharmaceutically acceptable salts of Formulae I-IV.
In still another embodiment, the invention is directed to a method for treating or preventing inflammation and/or an inflammatory response in the subject, comprising: administering to a subject an anti-inflammatory amount of more or more compounds having the formulae (Formulae I-IV): 
R1, R2 and R3 are each independently, selected from the group consisting of hydrogen, F, Cl, Br, I, CH3 and substituted or unsubstituted, linear or branched alkyl, alkoxy, aryl, aralkyl or heteroaryl groups. Y1, Y2, Y3, Y4, and Y5 are each independently selected from hydrogen atoms or lower alkyl groups. X1 is an oxygen atom, a sulfur atom, an Nxe2x95x90N group, a methylene or, NR5, wherein R5 is a hydrogen atom or a substituted or unsubstituted, linear or branched alkyl, aryl, aralkyl or heteroaryl group. X2 is an OH group, SH, CH3, or NR6R7, wherein R6 and R7 are each independently, a hydrogen atom or a substituted or unsubstituted, linear or branched alkyl, aryl, aralkyl or heteroaryl group. A1, A2, A3, and A4 are each independently, a substituted or unsubstituted aromatic or nonaromatic carbocyclic or heterocyclic group. Preferably, carbonxe2x80x94carbon bonds are not formed between one or more of C1 and C4, C2 and C5, and C3 and C6 carbon atoms. The present invention also includes pharmaceutically acceptable salts of Formulae I-IV.
In still another embodiment, the present invention is directed to a method of screening for a compound which modulates phospholipase D (PLD) activity. The method includes combining the compound with phospholipase D (PLD), thereby forming a mixture and treating the mixture with phosphatidylcholine, such that a cleavage reaction between phosphatidylcholine and PLD can occur, resulting in generation of phosphatidic acid and choline. The amount of choline produced is evaluated such that a compound which modulates PLD activity is determined. In a preferred embodiment, the compound increases cleavage of phosphatidylcholine by PLD.
In still yet another embodiment, the present invention is directed to a method of screening for a compound which modulates intracellular signaling. The method includes combining a compound with phospholipase D (PLD), thereby forming a mixture and treating the mixture with phosphatidylcholine, such that a cleavage reaction between phosphatidylcholine and PLD occurs, resulting in generation of phosphatidic acid and choline. The amount of choline produced is evaluated, such that a compound which modulates intracellular signaling is determined.
In another embodiment, the invention is directed to a method of screening for a compound which associates with protein phosphate-sensing domains. The method includes contacting a Gst-Grb2 fusion protein complexed to a support with a labeled lipid compound with and evaluating the amount of labeled compound associated with the protein. The method can further include treating the labeled lipid compound associated with a competing compound and evaluating the amount of labeled compound removed from the Gst-Grb2 fusion protein.
In still another embodiment, the invention is directed to a method of screening for a compound which modulates the production of inositol triphosphate. The method includes treating polymorphoneutrophils with a stimulation agent, causing activation of cell, thereby producing inositol phosphate and treating the activated cells with a modulating compound. The effect of the modulating compound is measured on production of the inositol phosphate. A preferred stimulation agent is fMLP. A preferred modulating compound is PSDP, e.g., an inhibititory compound.
In yet another embodiment, the invention is directed to a method of screening for a compound which modulates neutrophil activation. The method includes treating neutrophils with a stimulation agent, causing activation of the neutrophils, thereby producing inositol phosphate and treating the activated neutrophils with a modulating compound. The effect of the modulating compound is measured on production of the inositol phosphate. A preferred stimulation agent is fMLP. A preferred modulating compound is PSDP, e.g., an inhibititory compound.